Growth Failure in a Series of Iranian Patients with Juvenile Idiopathic Arthritis

Background: Juvenile Idiopathic Arthritis (JIA) is accompanied by growth failure, mostly occurring due to chronic inflammation and use of corticosteroids for treatment. The aim of our study was to determine the prevalence of short stature in JIA patients and possible systemic disorders which may affect the growth pattern in this group of patients. Methods: In this cross-sectional study erformed from June 2014 to May 2015, JIA patients with a history of more than one-year treatment were examined by an endocrinologist and based on their height standard deviation score (SDS) two groups were determined: Group A > -2SD and group B < -2SD. Complete blood count, thyroid function tests and 25OHD3 level were assessed in both groups, but other laboratory tests, including liver and renal function tests, growth hormone stimulation test, urine analysis and culture, as well as left hand and wrist X-ray for bone age determination, were done in group B. Results: Of 117 JIA patients who were enrolled, 41 patients were under -2SD (19% of pauciarticular, 62% of poly articular and 33% of systemic onset). The mean height SDS in group B was -3.48±1.28 (compared to -0.9±0.8 in their parents). We found hypovitaminosis D in 73% of our patients. The prevalence of subclinical hypothyroidism was 7.4% (5% of group A and 9.7% of group B). Twenty-four percent (10 patients) of group B did not respond to growth hormone (GH) stimulation test and 14.6% of them (6 patients) were possibly GH resistant. Liver function tests and renal function tests were normal in all the patients. There was no difference between 2 groups in hypothyroidism and hypovitaminosis D but polyarticular type of the disease was associated with short stature (P Value < 0.000). Conclusions: Growth failure is common in JIA patients. So they, especially those with polyarticular type, need to be visited periodically by an endocrinologist.